The present invention is related to an electronic metering apparatus for metering liquids.
Electronic metering apparatuses for metering liquids have a drive with an electric motor and a displacer device driven by this motor, which comprises a cylinder with a plunger arranged movable therein, for instance. The displacer device is communicatingly connected with a replaceable pipette point, for instance. By means of the displacer device, an air cushion is dislocated, which aspirates liquid into the pipette point and ejects it from the same, respectively. In difference to these air, cushion pipettes, direct displacement pipettes have a replaceable syringe, which aspirates and ejects liquid, respectively. Pipette points and syringes are preferably disposable objects for single use, made from a plastic material.
Further, electronic metering apparatuses are in the state of the art, in which different modes of operation can be selected, like pipetting, dispensing and titrating, for instance. In these metering apparatuses, different parameters may be settable, the liquid volume to be picked up and to be delivered when pipetting, the liquid volume to be picked up and the liquid volumes to be delivered when dispensing or titrating and the plunger speeds when picking up and delivering the liquid, for instance.
Known electronic metering apparatuses have a plurality of operational controls, by which the mode of operation of the metering apparatus is selected, the respective parameters are set and the operation of the metering apparatus is controlled in particular. The handling of the known metering apparatuses is awesome. Furthermore, it is disadvantageous that the control of delivering and pickup of liquid takes place via one single button, which must be actuated in a predetermined manner for releasing and stopping the plunger movement, respectively, so that the operation of electronic metering apparatuses is strongly different from that of manual metering apparatuses.
In the operation, errors can occur because the user does not recognise the next reasonable operation step.
Departing from this, the present invention is based on the objective to provide an electronic metering apparatus which facilitates the operation for the user.
The objective is resolved by the electronic metering apparatus according to claim 1. Advantageous embodiments of the metering apparatus are indicated in the subclaims.